Does your chimney have issues with odor, or letting too much smoke in your home? A smelly chimney is unpleasant for anyone living in your home and can be embarrassing when you have friends visiting your home. Smoke entering your home can also cause odor issues, but can also cause eye irritation and can leave nasty smoke stains on your walls and furniture. A lot of the time these issues are caused by issues with airflow and air pressure within your home and can be solved somewhat simply with a chimney system inspection from a Chimney Safety Institute of America (CSIA) certified chimney technician like the ones at Northeastern Masonry & Chimney.
Your Home Air System
The air in your house is in constant motion, even if you don’t notice it. Generally, hot air moves towards the upper portions of your home while cooler, denser air stays in the lower portions of your home. However, there are many factors that can affect the airflow in your home. A general knowledge of your home’s airflow and what affects it can help solve odor and smoke issues caused by your chimney.
The stack effect occurs when warm get trapped in the upper areas of your home. This warm air is pushed out of small cracks in the roof and walls of your home. At the same time replacement air is drawn into the home. Somewhere in your home is a Neutral Pressure Plane (NPP). The warmer air above this plane has slightly higher pressure than the outside. The cooler air below the NPP has air pressure that is slightly lower than the outside. This means that the lower parts of your home will try to suck air in from outdoors.
Newer homes tend to be airtigh. Often times this means that fireplaces that are placed below the NPP will suck in air from outdoors through the chimney. This means that all the odors that are in your chimney will be drawn into the home. This will also cause smoke to be pushed into the home if your fire is not warm enough.
When high winds strike your home, it will cause high pressure on the side of your home being struck by the wind. If a window is opened on the downwind side of the house, it can cause a backdraft, meaning smoke will be drawn out of the fireplace. Instead of up the chimney.
What can I do?
There are a couple things that you can do to fight negative air pressure. First, you can prime your chimney before you light a fire. The cold air in your chimney flue will want to sink into your home once you open your damper. You can warm up your flue by rolling up a piece of newspaper, lighting it, and sticking up your chimney to warm it up will warm up your flue and prevent smoke from entering your home. Building a hotter fire will also reduce smoke coming into your home because hotter air is lighter and will pull air up the flue.
Lastly, smoke and air need to be able to flow freely up your chimney flue. Creosote buildup and debris inside your flue can cause airflow issues which, in turn, can lead to issues with smell and smoke. The best way to ensure smooth airflow in your chimney flue is to have your chimney inspected annually by a CSIA-certified chimney sweep. If you have questions related your home’s airflow, don’t hesitate to contact Northeastern Masonry & Chimney today and have one of our CSIA-certified chimney experts inspect your chimney today!